The Influence of Internal Factors on the Growth Dynamics of Fish

This study investigates the influence of internal factors on growth dynamics in four Cyprinus carpio varieties: three Romanian strains (Frăsinet, Ineu, and Podu Iloaiei) and the ornamental Koi variety. The research aims to elucidate variety-specific growth patterns and their implications for aquaculture and ecological management. Fish were measured for total length, maximum height, and weight at four ontogenic stages: 7 days post-hatch, summer fingerlings (0⁺), one year and summer old (1⁺), and two years and summer old (2⁺). Weight Gain (WG), Specific Growth Rate (SGR), Relative Growth Rate (RGR), Fulton's condition factor, and profile index were calculated and analyzed. Results revealed significant intervariety differences in growth performance, body shape development, and physiological condition across life stages. The Romanian varieties showed superior growth performance at later stages, while Koi exhibited unique growth patterns. Fulton's condition factor and profile index varied markedly among varieties and life stages, indicating differential energy allocation and morphological adaptations. These findings highlight the complex interplay between genetic factors and developmental processes in carp varieties, providing valuable insights for selective breeding programs, aquaculture practices, and ecological management strategies. The study underscores the importance of variety-specific approaches in carp cultivation and conservation efforts.